Sinead O'Connor has canceled her 2012 tour due to concerns over her mental health.

"With enormous regret I must announce that I have to cancel all touring for the year as am very unwell due to bi polar disorder," she wrote on her website. "As you all know I had a very serious breakdown between December and March and I had been advised by my doctor not to go on tour but didn't want to 'fail' or let anyone down as the tour was already booked to coincide with album release," she continued. "So very stupidly I ignored his advice to my great detriment, attempting to be stronger than I actually am. I apologize sincerely for any difficulties this may cause."

In October of 2007 the Irish singer revealed on The Oprah Winfrey Show that she had been diagnosed with bipolar disorder in 2003, and this January she checked in to a hospital for depression, just two weeks after ending her marriage to Barry Herridge.

Brad Pitt and Angelina Jolie have ended their family vacation in South America.

The A-list twosome have been spending time with their large brood in the gorgeous Galapagos Islands.

While in South America, Jolie also visited Colombian refugees in Ecuador. The mom of six was recently appointed as a special envoy for the UNHCR.

See exclusive photos of their departure in our gallery below.

X17online was the first to report that Ashton Kutcher and Mila Kunis are definitely an item!

The two spent a romantic weekend just north of Santa Barbara in the town of Carpinteria, according to People.

Ashton and his former That 70's Show costar enjoyed a sushi dinner, bought sunflowers and blueberries at a roadside fruit stand ... and spent lots of private time together says a source.

The source adds:

"He was so in love with her for a while when they worked together. He thought she was a goddess, was always talking about how beautiful she is. But she was with Macaulay [Culkin] for a lot of that time and also just generally gave off a not interested vibe."

Sounds delish! Reps for both stars have denied that the pair are an item.

Rihanna stepped out for a late night bite in New York looking gorgeous without a stitch of makeup. We're so jealous!

The sexy songstress dined at DaSilvano restaurant ... working a snug silver dress, cropped jean jacket and strappy sandals.

Tres chic!

Lindsay Lohan has officially been signed on to play Elizabeth Taylor in the upcoming Lifetime movie, Liz and Dick.

The casting announcement came while Rosie O'Donnell was appearing on The Today Show with Matt Lauer and guest Donny Deutsch.

After hearing Lilo had landed the role, O'Donnell said:

"I feel very sorry for her ... I think she needs a lot of time away ... She's had a lot of trouble doing every single movie, including SNL. She was out and not in rehearsal. I think she's not in a place to work."

Deutsch said to Rosie, "She's our generation's Elizabeth Taylor."

Rosie replied:

"You're out of your mind! You're a crackhead! The last thing she did good she was sixteen. I don't think she's right for the role and I don't think she's capable at this point to portray that character."

Yikes! The movie's producer, Larry Thompson, feels differently. He tells E! News. "Well, we have more than a Plan B actually ... [because] Lindsay Lohan may be the most insured actress that ever walked on a soundstage."

Kim, Khloe, and a pregnant Kourtney Kardshian joined mom Kris Jenner made an appearance on the red carpet to support the opening of Scott Disick's new restaurant RYU, in the Meatpacking District of NYC, while Kanye West slipped in though the back door!

Disick's posh new restaurant will offer unique Japanese-inspired cuisine and world-class cocktails in a chic dining experience, which is perfect for elite clientele such as the Kardashians!

The newest season of Keeping Up is currently filming the girls' week in NYC, which will also include a behind-the-scenes look at last night's restaurant opening!

Yikes!

She's been MIA for quite awhile, but Helen Hunt stepped out for lunch in Brentwood looking less than Oscar-worthy as she showed off an unflattering makeup-free look, on Monday afternoon.

The What Women Want star has been taking a break from big screen flicks these days, but she is gearing up to join fellow actress Laura Linney in a special Juilliard gala performance at the prestigious school in NYC. later this month.

After three long years of remodeling, Simon Cowell's $25 million mansion is finally suitable enough for the X Factor mogul to settle in!

The sprawling five-bedroom estate comes equipped with a state-of-the-art gym (so Simon can look good in those extra-tight tees!), a luxury spa with a wet steam room, a custom-made media room with a bar and plush leather seating for 20, a gallery to display Cowell's countless gold and platinum records and awards, an indoor lap pool, and separate staff quarters for a live-in butler and maid.

It's a bummer that his most recent ex-fiancee won't be joining him in the lavish sprawling estate, but luckily he bought Mezhgan Hussainy her very own $8 million abode as a consolation prize!

Welcome home, Simon!